Manufacture of collapsible tubes



Aug. 19, 1947. F. w. SEYBQLD MANUFACTURE OF GOLLAPSIBLE TUBES Filed March 50, 1943 2 Sheets-Sheet 1 m ,Wm fm O m i lNvEN-roR F/edefzcl* 144 Jyald- Aug.. 19, 1947. F. w. si-:YBOLD MANUFACTURE DE COLLAPSIBLE TUBES Filed March 3o, 1943 2 Sheets-Sheet 2 1 n I i l n l l l l l1 ATTORNEYS Patented ug. i9, i947 MANUFACTURE F COLLAPSIBLE TUBES Frederick W. Seybold, Westield, N. J., assigner to American Type Founders, Inc., Elizabeth, N. J., a corporation of New Jersey Application March 30, 1943, Serial No. 481,092

(Cl. 3S-36.5)

7 Claims.

This invention relates to collapsible tubes and more particularly to an improved method of making collapsible tubes.

Collapsible tubes are extensively used for packaging various materials in plastic, semi-plastic and liquid form, such as tooth paste, shaving cream, cosmetics, food, cements, glues, paints, polishes and the like. Heretofore such tubes have been practically universally made of metal. Due to the present shortages of the metals heretofore used in the manufacture of such tubes, it has `been proposed to form collapsible tubes of paper or other non-metallic materials of sheet or film form.

One of the difiiculties encountered in the attempts to produce such tubes has been the provision of a conical shoulder and threaded neck of suliicient rigidity. The metallic collapsible tubes heretofore used have been formed by extrusicn and it has been the practice to provide a tube having a thin walled body for collapsibility, but having a shoulder and a reduced neck of comparative rigidity. In attempting to form tubes of paper or other iilm or sheet material it has been the practice to form the neck and shoulder separately of different material and the diiiiculties heretofore encountered have been mainly in securing the body of the tube to the shoulder.

It has now been proposed to form a collapsible tube of a tubular blank and spin a portion of the blank over the upper end which forms the shoulder and neck to shape the shoulder and neck and to crimp the excess material to produce a shoulder and neck portion of several thicknesses.

The present invention is an improvement over the tube just described and the method of manufacturing it. Instead of using a tubular blank of greater length than the tube and spinning the excess material over the shoulder and neck to shape it and form a shoulder and neck of several thicknesses, I provide a preformed blank from which two tubes are made having increased thickness of material at the portion of the blank which will form the shoulders and necks of the tubes. This blank is then spun to crimp or fold the paper or other film material forming the neck and shoulder and then cut to produce two tube blanks.

In the accompanying drawings I have shown several embodiments of the invention. In this showing:

Fig. 1 is an end view of a sheet of material for forming a tubular blank from which two tubes are constructed;

Fig. 2 is a front view of the tubular blank;

Fig. 3 is a View similar to Fig. 1 showing a modied form of the invention;

Fig. 4 is a front view of the tube blank made therefrom;

Fig. 5 is a view similar to Fig, 1 of another form of the invention.

Fig. 6 is a front View of the tubular blank made therefrom;

Fig. '7 illustrates the initial position of a tubular blank on a mandrel for forming a pair of tubes;

Fig. 8 is an illustration, partly in section, of

Fig. 9 is a plan View of a tube at the completion of the step shown in Fig. 8;

Fig. 10 is a View similar to Fig. 8 showing the completion of the forming operation; and

Fig. 11 is a side elevation ofthe end portion of a tube with parts shown in section.

Various materials may be used in the manufacture of collapsible tubes according to the present invention. Grades of paper or other fibrous sheet materials having the necessary properties may be employed. I may also use many of the plastic films or sheets now available on -the market, as for example, the Various cellulose base films of the type of Cellophane, er resin base films of the type of Vinylite, or rubber base films, such as the product Pliofilm The ma terial employed in the manufacture of the collapsible tube will depend primarily upon the nature of the product to be packaged in the tube. The material used should be thermoplastic or heat sealing. If paper or other material is used which is not thermoplastic, a coating of thermoplastic material should be applied thereto.

Referring to Figs. 1 and 2 of the drawings, a blank oi suitable material is folded laterally to provide end portions land 2 substantially equal in length to the body portion of the tube to be produced and an intermediate portion 3 ofl a length greater than the lengthof the shoulders and necks of the tubes. As shown, the intermediate portion is produced by folding a strip of material between the two end portions providing sealed in any suitable manner, `depending Vupon the material from which the tube is made.

Instead of folding the blank as 'shown in Fig. 1, it may be folded to produce a portion from which the necks of the tubes are to be made of five thicknesses. This is accomplished by means of an inner fold 'I and intermediate folds 8 and 9 formed in the central portion of the sheet I of material. This material is likewise cut of a proper width to form the circumference of the tube and a lapped joint and the lap II cemented in any suitable manner.

Instead of either of the procedures heretofore outlined, a sheet I2 of suitable length is provided with an intermediate strip I3 secured thereto in any suitable manner and formed into a tube as shown in Fig. 6 of the drawings.

Either of the forms of tubes illustrated in Figs. 2, 4 and 6 of the drawings is then placed on aligned mandrels I l and I5 and secured thereto by suitable holding devices or clamps Iii and I'I to prevent circumferential slippage. As shown, the mandrels are provided with cone-shaped ends I8 and I9, or these ends may be shaped in any way corresponding to the shape of the shoulder of the tube to be produced. The two mandrels are provided with central bores for the reception of a pin 20 which has a diameter equal to the desired internal diameter of the neck portion of the tube to be produced.

With the parts shown in the position illustrated in Fig. 7 of the drawings and with the eXtra thicknesses of material spanning the space between the two mandrels, one or both of the mandrels is then rotated with respect to the other and moved toward the other mandrel at the same time. The mandrels are moved toward each other until the distance between the conical ends is equal to or somewhat more than twice the length of the neck of a finished tube. This action twists the unsupported portion of the blank lying between the mandrels causing it to pucker inwardly and follow the contour of the mandrels and of the pin 2U. Because of the excess material provided in the blank, the spinning operation results in a pleating or crimping of the material over the conical heads of the mandrels and the pin 20, producing a shoulder and neck having a plurality of folds of material as illustrated in Figs. 8 and 9 ofl the drawings.

When the spinning operation has been completed, a pair of forming jaws 22 and 23 (see Fig. 8) are brought into position on each side of the blank to'nally shape the necks and shoulders, seal the layers or folds of material forming the necks and shoulders, and divide the blank into a pair of tubes. 'Ihe inner faces of the jaws are semi-cylindrical to permit application of pressure to the entire surfaces of the necks and shoulders. The jaws are provided with suitable heating elements 24 to heat seal the various layers of the necks and shoulders of the tubes to each other. The central portion 25 of the jaws which surrounds the neck portion, when in position, is also shaped to form the threads 26 on the neck portions. Adjacent each end of the central portion the forming jaws are provided with cone sections 3| which form and seal the pleated layers of the shoulders. The angle of the mandrel cones I8 and I9 is larger than the cone angle of the sections 3| of the jaws to accommodate the increase in material near the neck portion when the forming operation is carried out. When the jaws are in immediate contact, the volume of plastic material in the neck portion is less than the volume of plastic material of a completed tube. Thereafter both mandrels are moved toward each other into the cone sections of the forming jaws, squeezing additional material into 4 the threads as well as sealing the pleats of the shoulders together.

Fig. l1 shows the upper end of the tube with the shoulder 29 formed of several thicknesses of material and with the threaded neck 2S. A cap 35i of any suitable material may be arranged on the threaded neck as is now customary in connection with the forms of collapsible tubes now in use.

I claim:

1. The method which comprises forming a tubular blank having an intermediate portion of greater thickness than the end portions, supporting the ends of the blank, rotating one end of the blank with respect to the other while moving the ends toward each other to crimp and shape the intermediate portion of the blank to form the necks and shoulders of a pair of tubes, and severing the formed blank to form a pair of tubes.

2. There herein described method which comprises supporting a blank having an intermediate portion of greater thickness than the end portions on a pair of aligned mandrels and a central spindie, rotating one of the mandrels with respect to the other while holding the blank against circumferential slippage and moving one of the mandrels toward the other to crimp the material between the mandrels into a multiplicity of folds following the shape of the ends of the mandrels and surrounding the central spindle to form a neck portion, and severing the neck portion to form a pair of tubes.

3. The herein described method which comprises supporting a blank having an intermediate portion of greater thickness than the end portions on a pair of aligned mandrels and a central spindle, rotating one of the mandrels with respect to the other while holding the blank against circumferential slippage and moving one of the mandrels towar the other to crimp the material between the mandrels into a multiplicity of folds following the shape of the ends of the mandrels and surrounding the central spindle to form a neck portion, heating and pressing the material surrounding the central spindle and the ends of the two mandrels, and severing the neck portion to form a pair of tubes. Y

4. A collaspsible tube of sheet material comprising a tubular body portion, and a shoulder and neck integral therewith, the shoulder and neck being cf greater rigidity than the body portion, the tube being formed by twisting a blank having greater thickness in the portion thereof from which the shoulder and neck are to be formed than in the other portions to produce a multiplicity of small folds in the shoulder and neck.

5. A collaspsible tube of sheet material comprising a tubular body portion, and a shoulder and neck integral therewith, the shoulder and neck being of greater rigidity than the body portion, the tube being formed by twisting a blank having greater thickness in the portion thereof from which the shoulder and neck are to be formed than in the other portion, to produce a multiplicity of small folds in the shoulder and neck, and externally threading the neck.

6. A collapsible tube of sheet material comprising a tublar body portion, and a shoulder and neck integral therewith, the shoulder and neck being of greater rigidity than the body portion, the tube being formed by shaping a blank having a greater thickness in the portion thereof from which the shoulder and neck are to be formed than in the other portion, and by twisting that portion of the blank to crimp the material of the 5 shoulder and neck into a multiplicity of small folds.

'7. The method of making collapsible tubes which comprises supporting the ends of a tubular blank having a portion of greater thickness than the remainder, and rotating one end of the blank with respect to the other to crimp and shape the portion of the blank of greater thickness and form the shoulder and neck of a tube.

FREDERICK W. SEYBOLD.

REFERENCES CITED The following references are of record in the file of this patent:

Number UNITED STATES PATENTS Name Date Campbell Apr. 5, 1938 Moore June 14, 1938 Nicolai Jan. 19, 1892 Tome Oct. 7, 1941 Johnson Oct. 6, 1931 

